XRef -- A cross reference to another part of the document


Content Model

XRef ::=


Common attributes





Tag Minimization

The start-tag is required for this element. The end-tag is optional, if your SGML declaration allows minimization.

Parameter Entities



The XRef element forms a cross-reference from the location of the XRef to the element to which it points. Unlike Link and the other cross-referencing elements, XRef is empty. The processing system has to generate appropriate cross-reference text for the reader.

Processing expectations

If the Endterm attribute is specified, the content of the element pointed to by Endterm must be used as the text of the cross-reference, otherwise it is up to the application to generate appropriate cross reference text from the element pointed to by Linkend.

If the object pointed to has a specified XRefLabel, that should be used as the cross-reference text.


These elements contain XRef: Application, Attribution, BiblioMisc, BridgeHead, Citation, CiteTitle, Comment, Emphasis, entry, ForeignPhrase, GlossSee, GlossSeeAlso, GlossTerm, LineAnnotation, Link, LiteralLayout, LoTentry, Member, MsgAud, OLink, Para, Phrase, Primary, PrimaryIE, ProductName, ProgramListing, Quote, RefEntryTitle, RefPurpose, Screen, ScreenInfo, Secondary, SecondaryIE, See, SeeAlso, SeeAlsoIE, SeeIE, Seg, SegTitle, SimPara, Subtitle, Synopsis, Term, Tertiary, TertiaryIE, Title, TitleAbbrev, ToCback, ToCentry, ToCfront, ULink.


In some contexts, the following elements are allowed anywhere: BeginPage, IndexTerm.



Endterm points to the element whose content is to be used as the text of the link.


Linkend points to the target of the cross reference.

See Also

Anchor, Link, OLink, ULink


Consider the following example:

<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook V3.1//EN">
<book><title>An Example Book</title>
<chapter id="ch01"><title>XRef Samples</title>
This paragraph demonstrates several features of
<listitem><para>A straight link generates the
cross-reference text: <xref linkend="ch02">.
<listitem><para>A link to an element with an
<sgmltag class="attribute">XRefLabel</sgmltag>:
<xref linkend="ch03">.
<listitem><para>A link with an
<sgmltag class="attribute">EndTerm</sgmltag>:
<xref linkend="ch04" endterm="ch04short">.

<chapter id="ch02">
  <title>The Second Chapter</title>
  <para>Some content here</para>

<chapter id="ch03" xreflabel="Chapter the Third">
  <title>The Third Chapter</title>
  <para>Some content here</para>

<chapter id="ch04">
  <title>The Fourth Chapter</title>
  <titleabbrev id="ch04short">Chapter 4</titleabbrev>
  <para>Some content here</para>

One reasonable rendering for the content of the first chapter of this book is the following:

This paragraph demonstrates several features of XRef.

Of course, in an online system, these references would also be links to the appropriate chapters.

For additional examples, see also Part.

Copyright © 1999 O'Reilly & Associates, Inc. All rights reserved.